Magnesium base alloy



t v 1, 1942 y 1 I 2,278,726

-UNlTED STATETSV PATENT OFFICE MAGNE 5 :1 armor John C. McDonald,Midland, Mich, assig'nor to The Dow Chemical Company, Midland, Mich, acorporation of Michigan I l 1 I I No Drawing. AppIicatlonOctoberA,19,40,"

' 1 $eriaiNo.359,681 1 invention relates t 3, magnesium The properties.set'for'th aboveaunder the term al1oy." ;It more particularly concerns"an alloyflw n d' fl tainedfiby, gfi st, rollins h ,ar this naturehaving. improved physical proper-q specimens at 550'F.fand1thereafter-annealing ties such as hish y geldv tensile Fatjvarious' temperatures through a range Commercially pure magnesiuniof'from'iflilt to 800-F. The properties selected only to a extent, as'astructural mate-v ior the table were those of the annealed specb rialbecause of itsrelatively'lowtensile mens which exhibited the maximumelongation. although itslightweightis The properties set forth; underthe term- "cold -a highly desirable :rolled were-obtained bysubjectinggspecime'ns V ings;-jiorgings, extruded forms, andi'he ,I 01which had first been hot rolled at a temperature .It is, thereforeytheprincipal objectoi' the ine 0! 550"F. to additional rolling in the coldstate. vention to provideianalloy. or magnesium which The propertiesselected for the table were those utilizes the light weightcharacteristic of mag'-. of the cold rolled specimens which showed thenesium and at thesame time superior greatest yield and tensile strength,while having strength characteristics, Y. l v at least a l per centelongation in 2 inches.

Other objects and advantages willbe apparent A comparison of theproperties listed in the as the description orthe-invention proceeds.above table shows the improvement in yield and My invention resides inthe discovery that a tensile strengths of my new binary alloy overmagnesium base alloy composed of from 0.1 to 10 similar properties ofpure magnesium. For exper cent of germanium, the balance being subample.it will be-npted that in the annealed state stantially possesses theaiorementhe yield strength of the new alloy is always tioned properties.The term magnesium used superior to that 01' sublimed magnesium whileherein and in the appended claims is intended nearly comparableimprovement in the tensile to include magnesium containing the ordinarystrength prevailsin both the annealed and cold impurities that are foundin the commercially rolled state. In addition, it will b noted thatpuremetal',such as traces of iron, copper, nickel, the yield strength inthe cold rolled state shows and silicon. fj.whilethe properties of hightensile improvement in most. of the range or the added and yieldstrengths are manifest over the entire alloying constituent. Theimprovement shown range =0! composition indicated, the most dein theabove compositions is representative of sirablecombination ofpropertiesisioundinthose the improvement shown throughout the rangealloys containing from 0.5 to 5 percent of gerof the alloying ingredientindicated. manium. The new alloy will be found most useful inthe Apreferred composition having superior yield production of castings,extruded forms, and the strength as well as highly improved tensilelike, wherein high tensile and yield strengths I strength is onecontaining 0.8 per cent of ger- 35. are highly desirable. m The newalloymay be compounded by any of The following table which lists some of thethe methods usually employed for melting and properties of rolled sheetmetal made from my alloying metals with magnesium, such as by addnewbinary and compares th Propertiel ing the germanium to a bath of moltenmagwith those of magnesium illustrates the improve- 40 nesium which ispreferably protected from oxidament in yield strength and tensilestrength of my 1 tion by suitable flux.

new alloy over that of magnesium; The mag- "I laim; nesium used inpreparing the new alloy and for V 1. A magnesium base alloy containingfrom 0.1 the purpous of comparison was obtained by subto 10 per cent ofgermanium, the balance being liming commercial magnesium. magnesium.

Table 2. A magnesium base alloy containing from 0.5 to 5 cent ofgermanium, the balance being magn um. ififi fi wanna? 3. A magnesiumbase alloy containinglirom 0.1

percent a to 10 per cent oiv germanium and characterized mum, 'r nailremainder-) semis satiiiih stre h g in sm m m by substantial improvementin at leastone oi -lM -im lbs.lsq.in. lbs.lsq.in. lbsJ J- the propertiesductility, tensile strength, and

251000 14 a! yield strengthascompared with magnesium with- --i g f 1,0001 e; out the germanium.

3,2 3% 2 a 1km 1,- c. sons 0.- McDONAIiD.

4.: 1mm 25,000 g

